This invention relates to cartoners and more particularly to cartoners for loading groups of articles in single tier or stacked tier format into cartons.
Apparatus and methods for grouping articles and inserting them into cartons in one or more layers or tiers are well known. For example, articles are fed in feed lanes at an angle toward a bucket conveyor. A device segregates a select number of articles in each lane to form a row of articles to be combined with other, like-formed rows from other lanes into a group. This group is transported downstream in a bucket and then inserted transversely from the bucket into an adjacent carton also moving downstream. Generally, bucket conveyors transport the formed groups in buckets in parallel with an adjacent carton conveyor, and the groups are sequentially transferred from the bucket conveyor, sometimes across an intermediate transfer conveyor, into the cartons. This is typically accomplished in the prior art by a barrel loader, for example, or by direct loading. Examples of such systems can be seen in U.S. Pat. Nos. 3,778,959 and 5,241,806.
When it is desirable to load a carton with two tiers or two stacked groups, one atop another, it is known that two of the single level devices, such as in U.S. Pat. Nos. 3,778,959 or 5,241,806 can be combined. Typically, a partition or slip sheet is inserted over the first lower group at a location between the formation of such a lower group and the formation of a second upper group. The upper group is then formed on top of the partition and the two, stacked groups and intermediate partition are loaded into a carton, tall enough to accept both groups, in a fashion similar to single level or single group loading. Such two-tier or dual-layer systems are shown in prior art patents such as U.S. Pat. Nos. 5,666,789 and 5,692,361. Such systems use the same flight bars for forming and transporting rows of articles and groups thereof in both upper and lower levels of groups. That is, the same flight bars extend through and are operational in both upper and lower group forming stations.
These systems have at least two inherent design limitations of major operational significance.
First, there is a matter of changeover costs where different articles are to be handled. In such systems, the devices metering the articles and forming the rows are flight bars attached to and extending from the structure of the bucket conveyors. Wedges are formed on the end of the flight bars to handle articles of particular diameter or varying article counts. The width of the bars and/or spacing therebetween must be changed when articles of different diameter or different counts of articles are to be cartoned. This requires a changeover of the flight bars or xe2x80x9cwedgesxe2x80x9d associated with each bucket of the bucket conveyor. Thus, the cost of changeover is, in part, a function of the number of buckets in the system and the down-time required to modify each one.
Accordingly, it has been one objective of the invention to reduce the number and cost of changeover parts, and the downtime necessary for any changeover in article size.
In another aspect of the inherent design of prior systems, and particularly in multiple layer systems, a partition or slip sheet is inserted by a sheet feeder into the moving line of grouped articles between the lower group forming apparatus located upstream, and the upper group forming apparatus located downstream. In that position, the sheet feeder and its attendant magazine are surrounded by the lower group forming apparatus, the adjacent infeed for the upper group, the upper group forming apparatus, and the bucket conveyor as well as perhaps the carton conveyor. This severely limits access to the sheet feeder and its associated magazine for resupply, maintenance and repair. Either access to the prior devices is limited, or the entire cartoner footprint must be unduly and expensively lengthened to provide an accessible area station for the feeder between major elements of lower and upper group forming operations.
Accordingly, it has been a further objective of this invention to provide an improved cartoner for multi-level groups of articles with a sheet feeder having improved access without requiring undue length extension of the cartoner""s footprint.
To these ends, the invention contemplates, in a preferred embodiment, a cartoner having an intermediate transfer conveyor separate and independent of an adjacent, longer bucket conveyor and extending alongside the bucket conveyor for so much length as required to select, receive and transfer select count rows of articles from respective article infeed lanes to the buckets of the bucket conveyor. The phrase xe2x80x9cseparate and independentxe2x80x9d means not attached to or part of the buckets of the bucket conveyor, but constituting a distinct conveyor. Article selecting or row defining wedges or transfer guides are carried on the intermediate transfer conveyor. These transfer guides extend into article feed lanes, intersect articles, select a count of articles in each lane to form a group row and transfer the row into the buckets. While the guides are indexed with the buckets, they are separate and independent, i.e. distinct therefrom. The guides are thus operational to define select count rows, but at the same time, only a relative few guides are required when compared to the number of buckets desired or used, since the transfer conveyor extends through only a short run adjacent the much longer bucket conveyor.
This is due to the fact that the intermediate transfer conveyor need only be so long as to present a transfer guide to select rows, and then move the rows along until transferred to a bucket. Thereafter, the guide can be returned for subsequent row selections and transfers. There are, in this invention, no article selecting or group or row forming devices or flight bars carried on the buckets themselves.
Accordingly, when it is desired to changeover the apparatus to handle articles of differing diameter or count, it is only necessary to change the few transfer guides and not a device on every bucket of the bucket conveyor. Since the transfer conveyor carrying the transfer guides is very short, it will be appreciated that each guide will select respective rows of articles for more than one bucket on the bucket conveyor for the layer in question. Thus, the number of changeover parts, costs and downtime is significantly reduced, as are the number of product engaging parts in the system.
And where a multiple layer or dual layer system is contemplated, it is appreciated that a further separate and independent second transfer conveyor, totally distinct, spaced and elevated from the bucket conveyor different than the first transfer conveyor for the other level, is used. Thus, each level of articles is acted on by a separate and distinct intermediate transfer conveyor. The intermediate transfer conveyor and transfer guides for one group level have no function with any articles of the other group level for the same carton. There are instead two separate intermediate conveyors and with separate sets of guides. While each guide may be changed when articles of different diameters or count are to be cartoned, the total number of changeover parts and downtime is still significantly less than if wedges or bars on each bucket of the longer bucket conveyor had to be changed.
Moreover, where dual tier cartoning is provided according to the invention, the use of two separate intermediate transfers provides a further unique advantage. In the past, since the group forming devices, herein called xe2x80x9cflight barsxe2x80x9d, extended laterally from the buckets, a dead plate was provided thereunder. The junction of the dead plate with the adjacent infeed conveyor typically presents a xe2x80x9cstumbling pointxe2x80x9d as the articles move from the infeed conveyor to the dead plate. When final cans in the lane are presented at the noted junction, without pressure from any upstream articles, their feed over junction is not positive. The articles are frequently fed partially or not at all onto the dead plate and can be spread or entirely missed by the flight bars. When the machine had to be cleared of all articles, pusher blocks or such devices were required to push the last articles from the infeed lanes positively onto the dead plate for pickup by flight bars and movement into the buckets. Otherwise there was no mechanism to move the last articles (not subject to pressure from upstream articles) laterally onto the dead plate and toward the buckets. Alternately, these last cans were removed by hand.
In this invention, the intermediate transfer for the lower tier does not extend into the area of group forming for the upper tier. Accordingly, there is no need to accommodate any space beside the bucket conveyor in the upper tier forming area for any flight bars from the lower tier. This means that a live conveyor can be placed directly next to the bucket conveyor for both the upper and lower tiers, without intervention of any dead plate. Accordingly, articles in the infeeds are positively conveyed and urged all the way into the buckets. There is no need for article pusher blocks or such to clear the infeed lanes by pushing the last articles in the lanes into the buckets. The cartoner can thus be run to empty without additional mechanisms for pushing the last articles over a dead plate into the buckets, or without manual intervention.
More particularly, in the previous art with a flight bar device extending from the bucket walls, the lower level could have a live conveyor next to the bucket conveyor. Conveyance of the last cans in the lane onto or over the dead plate was less than positive.
There is yet a further advantage of the invention which arises from the use of intermediate transfers without group or row selecting and forming devices (flight bars) extending from the buckets. In particular, it will be appreciated that such flight bars extend laterally and move in a path beside the bucket-conveyor. Where barrel loaders are used to push groups of articles from the buckets into cartoners, the barrel loader pushers move along beside the buckets and extend through the buckets to push the groups. These pushers must be disposed adjacent the buckets but spaced apart therefrom a distance sufficient to clear the lateral extension of the flight bars. This requires the stroke of each barrel loader pusher to also extend a distance equal to the width or lateral extension of these flight bars, as well as its normal loading stroke. Otherwise, the moving flight bars would hit the pusher ends.
In this invention, the intermediate transfer conveyor terminates upstream of any barrel loader. The barrel loader can thus be placed immediately adjacent the bucket conveyor, there being no such laterally extending flight bars from the buckets. The pusher stroke of the barrel loader can thus be shorter, as compared to prior devices. It does not have to also extend a distance equal to that width of the path of any laterally extending flight bars.
This is an important advantage. It will be immediately appreciated that a smaller barrel loader can be used, resulting in a smaller equipment footprint, higher speeds due to shorter stroke length can be obtained, or a smoother operational loading profile can be utilized. These features may be combined or attained separately for particular installations.
The invention also contemplates a unique partition or slip sheet feeding operation. Preferably, a sheet feeder and its associated magazine is disposed at an upstream end of the bucket conveyor. Partitions are fed onto rails extending along in a machine direction above the elongated path of the forming lower group in the bucket conveyor.
The partitions are fed and transported so that on start up, when the first lower group is formed, a partition conveyed above it is lowered onto that group so the upper group can be formed thereon. A full load of upper and lower groups with intervening partition is thus assured for the first carton to be filled. This invention thus places the sheet feeder and magazine out at the upstream end of the bucket conveyor where it can be easily accessed, preferably near the carton magazine where an operator can tend both carton blank magazine loading and partition magazine loading for the sheet feeder. Access is open and the footprint of the cartoner need not be unduly extended.
This eliminates the requirement to place the sheet feeder and magazine in the area between the lower and upper group forming stations as in the prior art. The upper and lower group forming stations need not be separated, as in the old systems, thereby unduly increasing the cartoner""s footprint.
Of course, it will be appreciated that the two aspects of this invention, i.e. the separate and independent transfer guide conveyors and the sheet feeder can be used together when desired, or independently of each other. For example, the independent transfer guide can be used in both single or dual tier cartoners, to the same advantage, even if a sheet feeder described herein is not used over the upstream end of the bucket conveyer.